package com.sky.interceptor;


import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyInterceptor implements HandlerInterceptor {
    //在目标方法执行之前
    //一般是请求判断是否合法还要给你发TV出现
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle...");
        String param = request.getParameter("param");
        if ("yes".equals(param))
            return true;
        else {
            request.getRequestDispatcher("/jsp/error.jsp").forward(request, response);
            return false;
        }
    }

    //在目标方法执行之后，是视图方法返回之前执行
    //对视图模型修改
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("PostHandle...");
        assert modelAndView != null;
        modelAndView.addObject("name", "Big Clever!!!");
    }

    //整个流程都执行完毕后执行
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("AlterCompletion...");
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }
}
